This invention relates to a disposable diaper for absorption and containment of body wastes and the like.
Japanese Utility Model Application Disclosure Gazette (Kokai) No. Hei5-15934 discloses a disposable diaper comprising a topsheet, a backsheet and a liquid-absorbent core disposed between these two sheets. An upper surface of the topsheet in front and rear waist regions of the diaper is covered with exudation-proof sheets each bonded along its peripheral edge except its inner edge to the topsheet by a sealing line. The exudation-proof sheets are not bonded to the upper surface of the topsheet along its inner edges so that body wastes may flow into spaces defined between the topsheet and the exudation-proof sheets and then be absorbed by an absorbent core covered with the topsheet therethrough.
However, the above-mentioned known diaper is inconvenient in that one or both of the spaces defined between the topsheet and the exudation-proof sheets may be almost permanently closed as the topsheet and the exudation-proof sheets are forced in contact with each other under pressure of a wearer""s belly and/or back. Even after such pressure has been removed, the spaces can not be opened again because there is no means biasing the spaces to be opened again. Consequently, once an amount of body wastes have reached the front and rear waist regions, such amount of body wastes may at least partially flow over the outer surface of the exudation-proof sheets and leak outward.
In view of the problem as has been described above, it is an object of the present invention to provide an improved disposable diaper enabling it to prevent body wastes from leaking outward from front and rear waist regions of a diaper.
According to the present invention, there is provided a disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the topsheet and the backsheet to form a front waist region, a rear waist region and a crotch region extending between the front and rear waist regions in a longitudinal direction orthogonal to a transverse direction of the diaper, the topsheet being covered, at least in one of the front and rear waist regions, with a liquid-resistant sheet bonded to a longitudinal end and transversely opposite side edges of the one of the front and rear waist regions; an elastic foamed member which is folded in two along a folding axis zone extending longitudinally thereof and has a first portion placed against an upper surface of the topsheet and a second portion placed against a lower surface of the liquid-resistant sheet being disposed between the topsheet and the liquid-resistant sheet in such a manner that the foamed member lies on an upper portion of the absorbent core in the one of the front and rear waist regions with the folding axis zone being held in the vicinity of the longitudinal end of the one of the front and rear waist regions; and the first and second portions cooperating with each other to form a pocket opening toward the crotch region and one of the first and second portions extends toward the crotch region over a distance longer than that over which the other extends toward the crotch region.
According to one embodiment of the present invention, a distance over which the second portion extends toward the crotch region is in a range of 25xcx9c35 mm and a distance over which the first portion extends toward the crotch region is in a range of 5xcx9c10 mm.
According to another embodiment of the present invention, a distance over which the first portion extends toward the crotch region is in a range of 25xcx9c35 mm and a distance over which the second portion extends toward the crotch region is in a range of 5xcx9c10 mm.
According to the present invention, said foamed member can be formed selectively by polyurethane foam, synthetic rubber foam or polystyrene foam so far as all of them being of soft type.